1. Technical Field
This invention relates to an absorbent article such as a disposable paper diaper, a sanitary napkin or the like, and more particularly to an absorbent article provided with an indicator means capable of identifying an excretion of body fluid such as urine or the like from an outer side.
2. Background Art
An absorbent article such as a disposable paper diaper, a sanitary napkin or the like, should provide a quality giving amenity to a wearer and usability to the user. In order to obtain the amenity, a water vapor permeable film is generally employed in this field. The level of water vapor permeability has become higher and higher from year to year. Further, in order to improve the usability, an indicator means informing the user (for example, a mother) of the excretion of the body fluid of the wearer (for example, a nursling) is in heavy usage. As the indicator means, there has been developed a water content indicator which quickly responds with a small amount of water content.
Previously, as the water content indicator provided in the absorbent article as mentioned above, there has been generally known an absorbent article in which a display element constituted by a water based ink or paint discolored by the water content is directly applied to an inner surface (that is, a skin contact surface) side of a base material sheet constituted by an unpigmented hydrophilic paper (refer, for example, to Japanese Unexamined Patent Publication No. 9-299401), or an absorbent article in which a hydrophilic composition discolored by a change of pH on the basis of the water content is directly applied to an inner surface of a liquid impermeable back sheet (refer, for example, to Japanese Unexamined Patent Publication No. 2003-210522).
However, in the conventional absorbent article provided with the water content indicator mentioned above, for example, in the case that it is stored in a warehouse at a time of transporting, or in the case that it is displayed at the store or the like, it has been a problem that the absorbent article is exposed to the outside air and the outside light, and the water content indicator is already reacted and discolored before being used. If the water content indicator is reacted and discolored before being used as mentioned above, it is hard to identify from the outer side whether or not the excretion of body fluid is actually executed. Further, in the case that a small amount of body fluid is excreted, it is more difficult to identify the excretion.
This invention has been made under the circumstances as described above, and its object is to provide an absorbent article which removes the defect of the absorbent article as mentioned above, which prevents the function from decreasing even if it is exposed to the outside air and the outside light in the transportation or the storage or the like, which is provided with a high sensitive water content indicator which can immediately identify the excretion from the outer side even if it is a small amount of body fluid, and which gives an amenity to a wearer and a usability to a user.